This invention relates to a contact structure of an electrical connector including a first connector having a plurality of electric contacts and a second connector having a plurality of electric contact elements for electrically connecting these electric contacts and the electric contact elements, and more particularly to an inspecting device for inspecting the performance of the first connector.
For electrically connecting contacts of electrical connectors, in general, the butt contact and the sliding contact have been used. The known sliding contact and a known inspecting device therefor will be explained by referring to FIGS. 7 to FIGS. 10A and 10B.
As shown in FIG. 7, a hitherto used electrical connector includes a first connector 10 and a second connector 20 which are brought into abutment against each other to electrically connect a plurality of electric contacts 12 made of solder or the like in the form of hemispherical protrusions provided on one surface of a connector plate 11 of the first connector 10 to a plurality of electric contact elements 26 provided on one surface of a board 22 of the second connector 20. Such an electrical connector has typically a plug and socket mechanism (not shown) for detachably connecting the first and second connectors 10 and 20.
In order to give an elasticity to the electric contact elements 26 of the second connector 20, its board 22 is formed with slits 24 to form small tongue-shaped movable pieces which are parts of the board 22 for elastically supporting the electric contact elements 26, respectively. With this construction, when the first connector 10 is urged toward the second connector 20 in the direction shown by an arrow T, the electric contacts 12 of the first connector 10 cause the electric contact elements 26 of the second connector 20 to move downwardly as viewed in FIG. 7.
The known inspecting device for inspecting the performance of such an electrical connector, particularly, the first connector described above will be explained by referring to FIG. 8. The second connector 20 is fixed by a housing 48 and a block 52 so as to be embraced therebetween. The second connector 20 extends with its edges from the housing 48 and the block 52 and fixed to a hard substrate or board by soldering. The housing 48 includes a fitting opening 66 into which the first connector 10 is inserted. A back-up plate 50 is arranged between the block 52 and the second connector 20 mounted thereon for maintaining the contacting pressure between the first and second connectors. The performance inspection will be effected by urging the first connector received in the fitting opening 66 of the housing 48 toward the second connector 20.
With the butt contact, if there are any dirt or foreign substances 40 (FIG. 9A) on the electric contact and electric contact element, a good electrical connection therebetween could not be obtained when they are caused to abut against each other. In order to overcome this problem, the sliding contact between the electric contact and the electric contact element has generally been employed so that the dirt or foreign substances on the contacting surfaces are wiped or removed by the relative movement between the electric contact and the electric contact element.
In more detail, as shown in FIGS. 9A to 9C, first an electric contact 12 of the first connector 10 contacts an electric contact element 26 at a contact point 29, and when the first connector 10 is then urged in the direction shown by an arrow U, the electric contact 12 slidably moves on the surface of the electric contact element 26 to a contact point 29'. However, during such a sliding movement, contaminations or foreign substances 40 are moved by the sliding electric contact 12 in the sliding direction so as to accumulate higher (FIG. 9A). FIG. 9B illustrates the electric contact 12 in FIG. 9A in two different positions 29 and 29' in one drawing. With such a higher accumulation 42, the electric contact 12 tends to ride over the accumulation 42 so that the electric contact 12 is rolled or inclined (FIG. 9C) as shown by an arrow V, causing a defective electrical connection between the electric contact 12 and the electric contact element 26.
With an electrical connector having such a contact structure, when the electrical connector is set in an inspecting device to inspect its performance, the defective electrical connection due to the accumulation described above would often be caused, making it impossible to effect a stable inspection.
In order to solve this problem, the inventors of the present application have proposed a contact structure in Japanese Patent Application No. H10-267,393 as shown in FIGS. 10A and 10B. As shown in FIG. 10A, a board 22 of a second connector 20 is formed with slits closely around electric contact elements 26 so that the electric contact elements 26 are elastically supported by small tongue-shaped movable pieces of the board 22 formed by the slits, respectively. Each of the small tongue-shaped movable pieces supporting the electric contact element is previously inclined at an angle .gamma. as shown in FIG. 10A. When the first connector 10 is fitted with the second connector 20, the electric contact 12 of the first connector 10 urges the electric contact element 26 supported by the small tongue-shaped movable piece of the board 22 to bring the electric contact element 26 into the oppositely inclined position at an angle .delta. as shown in FIG. 10B. The relation between the angles .gamma. and .delta. is .gamma.&gt;.delta..
However, such a contact structure suffers a disadvantage from the required inclination of the small tongue-shaped movable pieces at the angle .gamma. to increase in the number of steps for production.